Novel Azobenzene Homopolymers via Atom Transfer Radical Polymerization Initiated by an Azobenzene Derivative

2010 ◽  
Vol 663-665 ◽  
pp. 92-95
Author(s):  
Xin De Tang ◽  
De Jie Zhou ◽  
Nian Feng Han
Keyword(s):  
Atom Transfer Radical Polymerization ◽  
Radical Polymerization ◽  
Data Storage ◽  
Liquid Crystalline ◽  
Optical Switch ◽  
Optical Data Storage ◽  
Optical Data ◽  
Atom Transfer ◽  
Scanning Calorimetry ◽  
Crystalline Property

An azobenzene derivative substituted with a 2-bromoisobutyryl group was used as an initiator for the atom transfer radical polymerization of 2-[4-(4-ethoxyphenylazo)phenoxy]ethyl methacrylate) (MAZO). The resulting homopolymers (AZO-PMAZO) possess azobenzene moieties both in the main chain and in the side chain. Differential scanning calorimetry (DSC) and polarized optical microscopy (POM) preliminarily revealed the liquid crystalline property of these polymers. The novel liquid crystalline polymers are expected to act as the candidates in some promising areas including optical data storage, optical switch, and molecular devices.

A2BA2-Type Amphiphilic Liquid Crystalline Block Copolymers by ATRP: Synthesis and Characterization

2010 ◽  
Vol 428-429 ◽  
pp. 154-157 ◽  
Author(s):  
Xin De Tang ◽  
Nian Feng Han ◽  
Jing Xu
Keyword(s):  
Block Copolymers ◽  
Data Storage ◽  
Liquid Crystalline ◽  
Optical Switch ◽  
Gel Permeation Chromatography ◽  
Optical Data Storage ◽  
Optical Data ◽  
Esterification Reaction ◽  
Scanning Calorimetry ◽  
Hexyl Methacrylate

A2BA2-type amphiphilic liquid crystalline block copolymers containing azobenzene were synthesized by atom transfer radical polymerization (ATRP). The macroinitiator prepared by the esterification reaction between poly(ethylene glycol) (PEG) and 2,2-dichloroacetyl chloride was used to initiate the ATRP of 6-[4-(4-ethoxyphenylazo)phenoxy]hexyl methacrylate (M6C). The resulting macroinitiator and block copolymers were characterized by 1H NMR, gel permeation chromatography (GPC). Polarizing optical microscopy (POM) and differential scanning calorimetry (DSC) preliminarily revealed the liquid crystalline property of these block copolymers. These novel amphiphilic liquid crystalline block copolymers are promising in some areas, such as optical data storage, optical switch, and molecular devices.

Synthesis and Characterization of Polyacrylates Side-Chain Liquid Crystalline Polymer via Atom Transfer Radical Polymerization

2012 ◽  
Vol 535-537 ◽  
pp. 1516-1519
Author(s):  
Ying Gang Jia ◽  
Peng Tian ◽  
Kun Ming Song ◽  
Bao Yan Zhang
Keyword(s):  
Atom Transfer Radical Polymerization ◽  
Radical Polymerization ◽  
Liquid Crystalline ◽  
Gel Permeation Chromatography ◽  
Crystalline Polymer ◽  
Atom Transfer ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
H Nmr

Atom transfer radical polymerization (ATRP) of methacrylate liquid crystal monomer M (4-((4-(2-(acryloyloxy)ethoxy)benzoyl)oxy)phenyl 4-propylbenzoate) was carried out using CuBr/PMDETA complex as catalyst and 2-bromo-2-methyl-propionic acid ester as initiator. The obtained monomer M and polymer P was characterized via infrared spectroscopy and1H NMR. The phase behavior and mesomorphism were investigated by differential scanning calorimetry (DSC), polarizing optical microscopy (POM), and x-ray diffraction (XRD). The molecular weight and the structure of the polymers were identified with gel permeation chromatography and nuclear magnetic resonance.

Polystyrene–organoclay nanocomposites produced by in situ activators regenerated by electron transfer for atom transfer radical polymerization

2012 ◽  
Vol 32 (4-5) ◽  
pp. 235-243 ◽  
Author(s):  
Khezrollah Khezri ◽  
Vahid Haddadi-Asl ◽  
Hossein Roghani-Mamaqani ◽  
Mehdi Salami-Kalajahi
Keyword(s):  
Molecular Weight ◽  
Electron Transfer ◽  
Atom Transfer Radical Polymerization ◽  
Radical Polymerization ◽  
Polymer Matrix ◽  
Clay Content ◽  
Xrd Analysis ◽  
Size Exclusion ◽  
Atom Transfer ◽  
Scanning Calorimetry

Abstract A newly developed initiation system, activators regenerated by electron transfer (ARGET), was employed to synthesize polystyrene-organoclay nanocomposites via atom transfer radical polymerization (ATRP). ARGET ATRP was applied since it is carried out at significantly low concentrations of the catalyst and environmentally acceptable reducing agents. Conversion and molecular weight evaluations were performed using gravimetry and size exclusion chromatography (SEC), respectively. According to the findings, addition of clay content resulted in a decrease in conversion and molecular weight of nanocomposites. However, an increase of polydispersity index is observed by increasing nanoclay loading. The living nature of the polymerization is revealed by 1H NMR spectroscopy and extracted data from the SEC traces. X-ray diffraction (XRD) analysis shows that organoclay layers are disordered and delaminated in the polymer matrix and exfoliated morphology is obtained. Thermogravimetric analysis (TGA) shows that thermal stability of the nanocomposites is higher than the neat polystyrene. A decrease in glass transition temperature of the samples by increasing organoclay content is observed by differential scanning calorimetry (DSC). Transmission electron microscopy (TEM) reveals that clay layers are partially exfoliated in the polymer matrix containing 2 wt% of organomodified montmorillonite (PSON 2) and a dispersion of partially exfoliated clay stacks is formed.

Photoinduced Reorientation and Multiple Optical Data Storage in Photo-Cross-Linkable Liquid Crystalline Copolymer Films Using 405 nm Light

2006 ◽  
Vol 39 (9) ◽  
pp. 3245-3251 ◽  
Author(s):  
Nobuhiro Kawatsuki ◽  
Kunihisa Kato ◽  
Tomoko Shiraku ◽  
Takeshi Tachibana ◽  
Hiroshi Ono
Keyword(s):  
Data Storage ◽  
Liquid Crystalline ◽  
Optical Data Storage ◽  
Optical Data ◽  
Copolymer Films

Synthesis of poly-2-hydroxyethyl methacrylate–montmorillonite nanocomposite via in situ atom transfer radical polymerization

2008 ◽  
Vol 23 (12) ◽  
pp. 3316-3322 ◽  
Author(s):  
Ayhan Oral ◽  
Talal Shahwan ◽  
Çetin Güler
Keyword(s):  
Atom Transfer Radical Polymerization ◽  
Radical Polymerization ◽  
Interlayer Spacing ◽  
Solvent System ◽  
Polymerization Reaction ◽  
Atom Transfer ◽  
Scanning Calorimetry ◽  
Copper Bromide ◽  
Transmission Electron

The poly-2-hyroxyethyl methacrylate (PHEMA)/clay nanocomposite was synthesized by in situ atom transfer radical polymerization (ATRP) from initiator moieties immobilized within the silicate galleries of the clay particles. To produce organically modified montmorillonite (MMT) that has ATRP initiator moiety, a new catalyst that consists of quaternary ammonium salt moiety and an initiator moiety was synthesized. This initiator was intercalated into the interlayer spacing of the MMT. The polymerization reaction was carried out in a mixed solvent system consisting of methyl ethyl ketone and 1-propanol at 50 °C, using the initiator that has been already synthesized with a copper bromide catalyst. The 2, 2′-bipyridyl (bpy) complex was used as ligand. The products were characterized via Fourier transform infrared, nuclear magnetic resonance (1H NMR, 12C NMR), transmission electron microscopy, x-ray diffraction, thermogravimetric analysis, and differential scanning calorimetry.

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